Step 1: What you need

-1/4" Female phono connector (guitar jack, whatever you want to call it)
-Soda can
-Piezoelectric buzzer, mine is quite large and came from a telephone ringer
-Some wire, both stranded type (if your leads from the piezo element aren't long enough) and safety wire (if you want a super ghetto attachment system like me)

Step 2: Connect the leads

I was lucky, the leads from my piezoelectric thingy were long enough to reach from one end of the soda can to the other. It yours do not, solder on some more wire to extend them.

Now, connect the black lead to the part of the 1/4" phono jack that is like a ring; the ground. Next connect the red one on to the part that connects to the J looking thing; the positive.

You should end up with something looking like this \/

Step 3: Removing the "lid" off the can.

Now we need to take the top out of the can, you can do this by cutting but I'll be highlighting the cool kid way.

The way I did it was to sand lip on the drinking side on a belt sander until the "lid" relased. If you don't have a belt sander, well, figure something out, it's not to hard.

Step 4: Cut a hole in the "lid"

Now we need to cut a hole in the lid for the piezo element to stick through.

I traced out my buzzer first, then started a cut with a dremel, but then I got lazy and just ripped it from there (beast, I know). I of course cleaned up the jagged rip marks with a sanding bit.

Then test fit! Cool, it fits!

Step 5: Put a hole in it.

You could probably just smash a hole through, but either way, I drilled a hole in the bottom for my jack to screw into.

Yeah, awesome project !!! I've just tried to make it this afternoon, and it's amazing ! I only replaced safety wire by gaffa or duct tape... with an awful french beer can (excuse my poor english... ).Using a plastic membrane (as plastic bag, why not?) in place of the can top with the piezo glued on (without plastic shield) could be another experience to make... with large and thin piezos.Thanks a lot, you give me many ideas...